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/*
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 * Copyright (c) 2007-2012, Stephen Colebourne & Michael Nascimento Santos
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *  * Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
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 *  * Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
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 *    may be used to endorse or promote products derived from this software
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package java.time.chrono;

import static java.time.temporal.ChronoField.EPOCH_DAY;

import java.io.IOException;
import java.io.InvalidObjectException;
import java.io.ObjectInput;
import java.io.ObjectInputStream;
import java.io.ObjectOutput;
import java.io.Serializable;
import java.time.LocalTime;
import java.time.ZoneId;
import java.time.temporal.ChronoField;
import java.time.temporal.ChronoUnit;
import java.time.temporal.Temporal;
import java.time.temporal.TemporalAdjuster;
import java.time.temporal.TemporalField;
import java.time.temporal.TemporalUnit;
import java.time.temporal.ValueRange;
import java.util.Objects;

/**
 * A date-time without a time-zone for the calendar neutral API.
 * <p>
 * {@code ChronoLocalDateTime} is an immutable date-time object that represents a date-time, often
 * viewed as year-month-day-hour-minute-second. This object can also access other
 * fields such as day-of-year, day-of-week and week-of-year.
 * <p>
 * This class stores all date and time fields, to a precision of nanoseconds.
 * It does not store or represent a time-zone. For example, the value
 * "2nd October 2007 at 13:45.30.123456789" can be stored in an {@code ChronoLocalDateTime}.
 *
 * @param <D> the concrete type for the date of this date-time
 * @implSpec This class is immutable and thread-safe.
 * @serial
 * @since 1.8
 */
final class ChronoLocalDateTimeImpl<D extends ChronoLocalDate>
    implements ChronoLocalDateTime<D>, Temporal, TemporalAdjuster, Serializable {

  /**
   * Serialization version.
   */
  private static final long serialVersionUID = 4556003607393004514L;
  /**
   * Hours per day.
   */
  static final int HOURS_PER_DAY = 24;
  /**
   * Minutes per hour.
   */
  static final int MINUTES_PER_HOUR = 60;
  /**
   * Minutes per day.
   */
  static final int MINUTES_PER_DAY = MINUTES_PER_HOUR * HOURS_PER_DAY;
  /**
   * Seconds per minute.
   */
  static final int SECONDS_PER_MINUTE = 60;
  /**
   * Seconds per hour.
   */
  static final int SECONDS_PER_HOUR = SECONDS_PER_MINUTE * MINUTES_PER_HOUR;
  /**
   * Seconds per day.
   */
  static final int SECONDS_PER_DAY = SECONDS_PER_HOUR * HOURS_PER_DAY;
  /**
   * Milliseconds per day.
   */
  static final long MILLIS_PER_DAY = SECONDS_PER_DAY * 1000L;
  /**
   * Microseconds per day.
   */
  static final long MICROS_PER_DAY = SECONDS_PER_DAY * 1000_000L;
  /**
   * Nanos per second.
   */
  static final long NANOS_PER_SECOND = 1000_000_000L;
  /**
   * Nanos per minute.
   */
  static final long NANOS_PER_MINUTE = NANOS_PER_SECOND * SECONDS_PER_MINUTE;
  /**
   * Nanos per hour.
   */
  static final long NANOS_PER_HOUR = NANOS_PER_MINUTE * MINUTES_PER_HOUR;
  /**
   * Nanos per day.
   */
  static final long NANOS_PER_DAY = NANOS_PER_HOUR * HOURS_PER_DAY;

  /**
   * The date part.
   */
  private final transient D date;
  /**
   * The time part.
   */
  private final transient LocalTime time;

  //-----------------------------------------------------------------------

  /**
   * Obtains an instance of {@code ChronoLocalDateTime} from a date and time.
   *
   * @param date the local date, not null
   * @param time the local time, not null
   * @return the local date-time, not null
   */
  static <R extends ChronoLocalDate> ChronoLocalDateTimeImpl<R> of(R date, LocalTime time) {
    return new ChronoLocalDateTimeImpl<>(date, time);
  }

  /**
   * Casts the {@code Temporal} to {@code ChronoLocalDateTime} ensuring it bas the specified
   * chronology.
   *
   * @param chrono the chronology to check for, not null
   * @param temporal a date-time to cast, not null
   * @return the date-time checked and cast to {@code ChronoLocalDateTime}, not null
   * @throws ClassCastException if the date-time cannot be cast to ChronoLocalDateTimeImpl or the
   * chronology is not equal this Chronology
   */
  static <R extends ChronoLocalDate> ChronoLocalDateTimeImpl<R> ensureValid(Chronology chrono,
      Temporal temporal) {
    @SuppressWarnings("unchecked")
    ChronoLocalDateTimeImpl<R> other = (ChronoLocalDateTimeImpl<R>) temporal;
    if (chrono.equals(other.getChronology()) == false) {
      throw new ClassCastException("Chronology mismatch, required: " + chrono.getId()
          + ", actual: " + other.getChronology().getId());
    }
    return other;
  }

  /**
   * Constructor.
   *
   * @param date the date part of the date-time, not null
   * @param time the time part of the date-time, not null
   */
  private ChronoLocalDateTimeImpl(D date, LocalTime time) {
    Objects.requireNonNull(date, "date");
    Objects.requireNonNull(time, "time");
    this.date = date;
    this.time = time;
  }

  /**
   * Returns a copy of this date-time with the new date and time, checking
   * to see if a new object is in fact required.
   *
   * @param newDate the date of the new date-time, not null
   * @param newTime the time of the new date-time, not null
   * @return the date-time, not null
   */
  private ChronoLocalDateTimeImpl<D> with(Temporal newDate, LocalTime newTime) {
    if (date == newDate && time == newTime) {
      return this;
    }
    // Validate that the new Temporal is a ChronoLocalDate (and not something else)
    D cd = ChronoLocalDateImpl.ensureValid(date.getChronology(), newDate);
    return new ChronoLocalDateTimeImpl<>(cd, newTime);
  }

  //-----------------------------------------------------------------------
  @Override
  public D toLocalDate() {
    return date;
  }

  @Override
  public LocalTime toLocalTime() {
    return time;
  }

  //-----------------------------------------------------------------------
  @Override
  public boolean isSupported(TemporalField field) {
    if (field instanceof ChronoField) {
      ChronoField f = (ChronoField) field;
      return f.isDateBased() || f.isTimeBased();
    }
    return field != null && field.isSupportedBy(this);
  }

  @Override
  public ValueRange range(TemporalField field) {
    if (field instanceof ChronoField) {
      ChronoField f = (ChronoField) field;
      return (f.isTimeBased() ? time.range(field) : date.range(field));
    }
    return field.rangeRefinedBy(this);
  }

  @Override
  public int get(TemporalField field) {
    if (field instanceof ChronoField) {
      ChronoField f = (ChronoField) field;
      return (f.isTimeBased() ? time.get(field) : date.get(field));
    }
    return range(field).checkValidIntValue(getLong(field), field);
  }

  @Override
  public long getLong(TemporalField field) {
    if (field instanceof ChronoField) {
      ChronoField f = (ChronoField) field;
      return (f.isTimeBased() ? time.getLong(field) : date.getLong(field));
    }
    return field.getFrom(this);
  }

  //-----------------------------------------------------------------------
  @SuppressWarnings("unchecked")
  @Override
  public ChronoLocalDateTimeImpl<D> with(TemporalAdjuster adjuster) {
    if (adjuster instanceof ChronoLocalDate) {
      // The Chronology is checked in with(date,time)
      return with((ChronoLocalDate) adjuster, time);
    } else if (adjuster instanceof LocalTime) {
      return with(date, (LocalTime) adjuster);
    } else if (adjuster instanceof ChronoLocalDateTimeImpl) {
      return ChronoLocalDateTimeImpl
          .ensureValid(date.getChronology(), (ChronoLocalDateTimeImpl<?>) adjuster);
    }
    return ChronoLocalDateTimeImpl
        .ensureValid(date.getChronology(), (ChronoLocalDateTimeImpl<?>) adjuster.adjustInto(this));
  }

  @Override
  public ChronoLocalDateTimeImpl<D> with(TemporalField field, long newValue) {
    if (field instanceof ChronoField) {
      ChronoField f = (ChronoField) field;
      if (f.isTimeBased()) {
        return with(date, time.with(field, newValue));
      } else {
        return with(date.with(field, newValue), time);
      }
    }
    return ChronoLocalDateTimeImpl
        .ensureValid(date.getChronology(), field.adjustInto(this, newValue));
  }

  //-----------------------------------------------------------------------
  @Override
  public ChronoLocalDateTimeImpl<D> plus(long amountToAdd, TemporalUnit unit) {
    if (unit instanceof ChronoUnit) {
      ChronoUnit f = (ChronoUnit) unit;
      switch (f) {
        case NANOS:
          return plusNanos(amountToAdd);
        case MICROS:
          return plusDays(amountToAdd / MICROS_PER_DAY)
              .plusNanos((amountToAdd % MICROS_PER_DAY) * 1000);
        case MILLIS:
          return plusDays(amountToAdd / MILLIS_PER_DAY)
              .plusNanos((amountToAdd % MILLIS_PER_DAY) * 1000000);
        case SECONDS:
          return plusSeconds(amountToAdd);
        case MINUTES:
          return plusMinutes(amountToAdd);
        case HOURS:
          return plusHours(amountToAdd);
        case HALF_DAYS:
          return plusDays(amountToAdd / 256)
              .plusHours((amountToAdd % 256) * 12);  // no overflow (256 is multiple of 2)
      }
      return with(date.plus(amountToAdd, unit), time);
    }
    return ChronoLocalDateTimeImpl.ensureValid(date.getChronology(), unit.addTo(this, amountToAdd));
  }

  private ChronoLocalDateTimeImpl<D> plusDays(long days) {
    return with(date.plus(days, ChronoUnit.DAYS), time);
  }

  private ChronoLocalDateTimeImpl<D> plusHours(long hours) {
    return plusWithOverflow(date, hours, 0, 0, 0);
  }

  private ChronoLocalDateTimeImpl<D> plusMinutes(long minutes) {
    return plusWithOverflow(date, 0, minutes, 0, 0);
  }

  ChronoLocalDateTimeImpl<D> plusSeconds(long seconds) {
    return plusWithOverflow(date, 0, 0, seconds, 0);
  }

  private ChronoLocalDateTimeImpl<D> plusNanos(long nanos) {
    return plusWithOverflow(date, 0, 0, 0, nanos);
  }

  //-----------------------------------------------------------------------
  private ChronoLocalDateTimeImpl<D> plusWithOverflow(D newDate, long hours, long minutes,
      long seconds, long nanos) {
    // 9223372036854775808 long, 2147483648 int
    if ((hours | minutes | seconds | nanos) == 0) {
      return with(newDate, time);
    }
    long totDays = nanos / NANOS_PER_DAY +             //   max/24*60*60*1B
        seconds / SECONDS_PER_DAY +                //   max/24*60*60
        minutes / MINUTES_PER_DAY +                //   max/24*60
        hours / HOURS_PER_DAY;                     //   max/24
    long totNanos = nanos % NANOS_PER_DAY +                    //   max  86400000000000
        (seconds % SECONDS_PER_DAY) * NANOS_PER_SECOND +   //   max  86400000000000
        (minutes % MINUTES_PER_DAY) * NANOS_PER_MINUTE +   //   max  86400000000000
        (hours % HOURS_PER_DAY) * NANOS_PER_HOUR;          //   max  86400000000000
    long curNoD = time.toNanoOfDay();                          //   max  86400000000000
    totNanos = totNanos + curNoD;                              // total 432000000000000
    totDays += Math.floorDiv(totNanos, NANOS_PER_DAY);
    long newNoD = Math.floorMod(totNanos, NANOS_PER_DAY);
    LocalTime newTime = (newNoD == curNoD ? time : LocalTime.ofNanoOfDay(newNoD));
    return with(newDate.plus(totDays, ChronoUnit.DAYS), newTime);
  }

  //-----------------------------------------------------------------------
  @Override
  public ChronoZonedDateTime<D> atZone(ZoneId zone) {
    return ChronoZonedDateTimeImpl.ofBest(this, zone, null);
  }

  //-----------------------------------------------------------------------
  @Override
  public long until(Temporal endExclusive, TemporalUnit unit) {
    Objects.requireNonNull(endExclusive, "endExclusive");
    @SuppressWarnings("unchecked")
    ChronoLocalDateTime<D> end = (ChronoLocalDateTime<D>) getChronology()
        .localDateTime(endExclusive);
    if (unit instanceof ChronoUnit) {
      if (unit.isTimeBased()) {
        long amount = end.getLong(EPOCH_DAY) - date.getLong(EPOCH_DAY);
        switch ((ChronoUnit) unit) {
          case NANOS:
            amount = Math.multiplyExact(amount, NANOS_PER_DAY);
            break;
          case MICROS:
            amount = Math.multiplyExact(amount, MICROS_PER_DAY);
            break;
          case MILLIS:
            amount = Math.multiplyExact(amount, MILLIS_PER_DAY);
            break;
          case SECONDS:
            amount = Math.multiplyExact(amount, SECONDS_PER_DAY);
            break;
          case MINUTES:
            amount = Math.multiplyExact(amount, MINUTES_PER_DAY);
            break;
          case HOURS:
            amount = Math.multiplyExact(amount, HOURS_PER_DAY);
            break;
          case HALF_DAYS:
            amount = Math.multiplyExact(amount, 2);
            break;
        }
        return Math.addExact(amount, time.until(end.toLocalTime(), unit));
      }
      ChronoLocalDate endDate = end.toLocalDate();
      if (end.toLocalTime().isBefore(time)) {
        endDate = endDate.minus(1, ChronoUnit.DAYS);
      }
      return date.until(endDate, unit);
    }
    Objects.requireNonNull(unit, "unit");
    return unit.between(this, end);
  }

  //-----------------------------------------------------------------------

  /**
   * Writes the ChronoLocalDateTime using a
   * <a href="../../../serialized-form.html#java.time.chrono.Ser">dedicated serialized form</a>.
   *
   * @return the instance of {@code Ser}, not null
   * @serialData <pre>
   *  out.writeByte(2);              // identifies a ChronoLocalDateTime
   *  out.writeObject(toLocalDate());
   *  out.witeObject(toLocalTime());
   * </pre>
   */
  private Object writeReplace() {
    return new Ser(Ser.CHRONO_LOCAL_DATE_TIME_TYPE, this);
  }

  /**
   * Defend against malicious streams.
   *
   * @param s the stream to read
   * @throws InvalidObjectException always
   */
  private void readObject(ObjectInputStream s) throws InvalidObjectException {
    throw new InvalidObjectException("Deserialization via serialization delegate");
  }

  void writeExternal(ObjectOutput out) throws IOException {
    out.writeObject(date);
    out.writeObject(time);
  }

  static ChronoLocalDateTime<?> readExternal(ObjectInput in)
      throws IOException, ClassNotFoundException {
    ChronoLocalDate date = (ChronoLocalDate) in.readObject();
    LocalTime time = (LocalTime) in.readObject();
    return date.atTime(time);
  }

  //-----------------------------------------------------------------------
  @Override
  public boolean equals(Object obj) {
    if (this == obj) {
      return true;
    }
    if (obj instanceof ChronoLocalDateTime) {
      return compareTo((ChronoLocalDateTime<?>) obj) == 0;
    }
    return false;
  }

  @Override
  public int hashCode() {
    return toLocalDate().hashCode() ^ toLocalTime().hashCode();
  }

  @Override
  public String toString() {
    return toLocalDate().toString() + 'T' + toLocalTime().toString();
  }

}
